On January 3 1962, “Gemini” became the official designation of the Mercury Mark II program. The name had been suggested by Alex Nagy of NASA Headquarters because the twin stars Castor and Pollux in constellation Gemini (the Twins) seemed to him to symbolize the program’s two-man crew, its rendezvous mission, and its relation to Mercury. Coincidentally, the astronomical symbol (II) for Gemini, the third constellation of the zodiac, corresponded neatly to the Mark II designation…